Trying to sort sections in descending order - objective-c

Question

self.sections = [[NSMutableDictionary alloc] init];
BOOL found;
for (NSDictionary *wine in sortedWines)
{
NSNumber *rate = [wine valueForKey:#"Rate"];
NSString *rateStr = [NSString stringWithFormat:#"%.f", [rate floatValue]];
found = NO;
for (NSString *str in [self.sections allKeys])
{
if ([str isEqualToString:rateStr])
{
found = YES;
}
}
if (!found)
{[self.sections setValue:[[NSMutableArray alloc] init] forKey:rateStr];}
}
for (NSDictionary *wine in sortedWines)
{[[self.sections objectForKey:[NSString stringWithFormat:#"%.f", [[wine valueForKey:#"Rate"] floatValue]] ] addObject:wine];}
// Sort:
for (NSString *key in [self.sections allKeys])
{[[self.sections objectForKey:key] sortUsingDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:#"Rate" ascending:NO]]];}
This code puts my wines in sections, but it won't sort them in descending order! Could it be because the NSNumber is transformed into NSString? I've tried to make a code using the NSNumber value:
self.sections = [[NSMutableDictionary alloc] init];
BOOL found;
for (NSDictionary *wine in sortedWines)
{
NSNumber *rate = [wine valueForKey:#"Rate"];
found = NO;
for (NSNumber *str in [self.sections allKeys])
{
if ([str isEqualToNumber:rate])
{
found = YES;
}
}
if (!found)
{[self.sections setValue:[[NSMutableArray alloc] init] forKey:rate];}
}
// Loop again to sort wines into their keys
for (NSDictionary *wine in sortedWines)
{[[self.sections objectForKey:[wine valueForKey:#"Rate"]] addObject:wine];}
// Sort each section array
for (NSString *key in [self.sections allKeys])
{[[self.sections objectForKey:key] sortUsingDescriptors:[NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:#"Rate" ascending:NO]]];}
But it gives a warning for
if (!found)
{[self.sections setValue:[[NSMutableArray alloc] init] forKey:rate];}
that says "Incompatible pointer types sending NSNumber ___strong to parameter of type NSString"
If I run the app it crashes with error -[__NSCFNumber localizedCaseInsensitiveCompare:]: unrecognized selector sent to instance 0x1e085810
What do I have to change to make it work and sort the sections in descending order? Thanks.

Answer 1

I don't know if the default selector for sortDescriptorWithKey:ascending: is now caseInsensitiveCompare:, I'm pretty sure it used to be just compare:. In any case, you can use sortDescriptorWithKey:ascending:selector:, instead, and pass compare: for the selector. I think that should fix your second error. Still not sure why you're getting that first error.

Answer 2

You would do much better (and we'd understand you better) if you formatted your code for legibility. Eg:
// Loop again to sort wines into their keys
for (NSDictionary *wine in sortedWines) {
NSArray* section = [self.sections objectForKey:[wine valueForKey:#"Rate"]];
[section addObject:wine];
}
// Sort each section array
NSArray* sortDescriptorArray = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:#"Rate" ascending:NO]];
for (NSString *key in [self.sections allKeys]) {
NSArray* section = [self.sections objectForKey:key];
[section sortUsingDescriptors:sortDescriptorArray];
}
Among other things, this makes debugging much simpler since you can stop and dump the section arrays.
Or, if you really liked it better the other way, I can highly recommend that you learn APL or LISP instead.